We’d like to put Mt Sutro Cloud Forest in the context of the bio-diversity in the Western part of San Francisco.

This is an 80-acre forest (including both the UCSF portion and the Interior Green Belt). That’s fairly large for a garden or a park. But in fact, it’s only one small habitat among many in the western part of the city.

The Westside habitat is quite varied: It has grasslands and meadows, chaparral and open woodlands, lakes and creeks – and dense forest. In particular, Sutro Cloud Forest. It’s this biodiversity thatsupports a range of plant and animal (including insect) life. (Unfortunately, much of it is subject to toxic herbicides, but Sutro Forest has been clear of the chemicals since 2008, and the Aldea Student Housing from 2009. Thanks, UCSF!)

This is a rough map (based on a 2005 USGS picture) of some of the major habitat areas of this part of the city.

This list does not include the beach, Lake Merced, the open woods and grassland on the grounds of the Laguna Honda Hospital. It excludes all the backyard habitats (mostly lawn, shrubs and flowers, with varying levels of pesticide use) and street trees.

But none of them are old-growth cloud forests like Mt Sutro Forest.

Some creatures – like migrating birds and butterflies – can access all these areas (which fall into the radius of a few square miles) and choose territories or terrain that suits their needs. Others – including some reptiles and flightless insects – may live and breed in a restricted but suitable place. Sutro Cloud Forest adds to the biodiversity of the area, providing dense forest cover for the creatures that need such forests and damp conditions. It’s worth preserving the integrity of its ecosystem.

Its interesting that the mission blue butterfly has actually returned to Twin Peaks where us nativists and our native species restoration efforts (including the selective and careful use of pesticides) have taken place. In other words, the restoration effort worked and has resulted in a breeding population of a near endemic and critically endangered species to its San Francisco habitat.

I hope the USFWS takes note and realizes the potential critical habitat expansion that exists on the undeveloped hilltops of SF. If we “phase out” the eucalyptus forests over time, return the native coastal scrub species (including lupine), we could also witness the return of the Mission Blue butterflies and potentially other endemic species to Mount Sutro and other hill tops on the SF Peninsula.

JMC, it would be more accurate to say that the Mission Blue has been returned to Twin Peaks. The Chron reported that one butterfly was sighted. We’re rooting for the Mission Blue, and admire the effort by the staff and volunteers who made this elaborate reintroduction. But so far, all we know is that at least one of over 250 2-3,000 eggs made it through.

This result from a multi-year effort. First, lupine, the food plant, was planted. Once that was established, 22 pregnant female butterflies were brought to Twin Peaks from San Bruno Mountain in April 2009. They were placed in net cages over lupine plants so they would lay their eggs there. Assuming 12 eggs each, that would be 264 eggs laid. [ETA: This calculation is wrong. The SF Examiner reported females lay about a dozen eggs in their lifetime; it’s actually “up to several hundred eggs” according to the Draft Restoration Plan. This would mean there could be 2-3000 eggs laid.]

With a life-cycle of about a year, this would be around the time for the hatching. Of course, spotting only one (male) butterfly doesn’t mean he’s alone. We hope there will be more, with enough of each sex, so they can find mates during their one-week lifespan. And we hope they find a Garlon-free area of Twin Peaks to lay their eggs.

Otherwise, it’s going to be like that old joke about the easiest way to make $1 million… (Start with $5 million.)

The fact that this batch succeeded (if it has) doesn’t mean that the next generation will make it. The starter group of 22 Blues were caged over selected lupine plants. We hope it was in a Garlon-free area. But will the butterflies make the same choice? It’s the caterpillars that must live near or on the ground, and would be vulnerable to toxins. Though you believe Garlon has little to no effect, one butterfly does not prove the point. And there’s no Garlon research on larvae; the insect research was on adult honey-bees.

Even if the reintroduction is successful – as we hope it will be – we do not see the value of destroying another flourishing eco-system in Sutro Cloud Forest. This region has other open spaces where lupine grows or could be grown, and Mission Blues reintroduced. That’s what diversity is about – having both the coastal scrub and the Sutro Cloud Forest.

Here’s an idea: Wouldn’t it be great to have two very different habitats, a life-filled mature forest and a grassland with its own wildlife, both existing so close together in San Francisco that both could be visited and enjoyed in a single morning’s walk? Oh, wait, that’s what we have now. (Assuming the gardening and butterfly farming on Twin Peaks is ultimately successful.)

It’s a perversion of “environmentalism” to want to destroy a productive habitat in order to replace it with a habitat that already exists right next door. Viva diversity in San Francisco.

As someone who lives here I can attest to just how many birds I see on Sutro, and I am very concerned about the impact of UCSF’s plans on them and the greater ecosystem when it comes to migrating birds.

{I apologize if this is not the best place for posting it, perhaps it is deserving of a stand alone mention or placed elsewhere on the site.}